From acc580e031ee8ed034bc1dec5a693d61c5eef00f Mon Sep 17 00:00:00 2001
From: Avril <flanchan@cumallover.me>
Date: Sat, 2 Oct 2021 14:06:16 +0100
Subject: [PATCH] Random: Added `next_*(min, max)`
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Fortune for cpprng's current commit: Future small blessing − 末小吉
---
 include/common.h |  7 +++++++
 src/rng.cpp      | 23 ++++++++++++++++-------
 src/rng/crand.c  | 11 +++++++++++
 src/rng/crand.h  |  3 +++
 4 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/include/common.h b/include/common.h
index 2433d34..bcc1d01 100644
--- a/include/common.h
+++ b/include/common.h
@@ -23,6 +23,13 @@ extern "C" {
 #define v_protected	_export(protected)
 #define v_hidden	_export(hidden)
 
+#define _fspec__readonly	__attribute__((pure))
+#define _fspec__pure		__attribute__((const))
+#define _fspec(x) _fspec__ ## x
+
+#define _rng_fpure  _fspec(readonly)
+#define _rng_fconst _fspec(pure)
+
 #define _rng_internal v_internal
 
 #define DEF(s, n) typedef s ## int ## n ## _t s ## n
diff --git a/src/rng.cpp b/src/rng.cpp
index 967bcd8..62f467a 100644
--- a/src/rng.cpp
+++ b/src/rng.cpp
@@ -2,12 +2,20 @@
 #include <rng.h>
 #include <range.h>
 
+constexpr const static util::range<f64> SAMPLE_RANGE { 0.0, 1.0 };
+
 template<typename T>
 static inline constexpr T _scale(f64 sample, T max)
 {
 	return (T)(sample * (f64)max);
 }
 
+template<typename T>
+static inline constexpr T _scale(f64 sample, T min, T max)
+{
+	return SAMPLE_RANGE.scale<T>({ min, max }, sample);
+}
+
 bool Random::next_bool() { return sample() < 0.5; }
 #define NEXT(T) T Random::next_ ## T(T max) { return _scale<T >(sample(), max); }
 #define NEXTT(n) NEXT(i ## n) NEXT(u ## n)
@@ -47,13 +55,14 @@ N_INTS
 
 #undef NEXTT
 #undef NEXT
+// ---
 
-//TODO: next_*(min, max)
+//next_*(min, max)
+#define NEXT(T) T Random::next_ ## T(T min, T max) { return _scale(sample(), min, max); }
+#define NEXTT(n) NEXT(i ## n) NEXT(u ## n)
 
-void __()
-{
-	util::range<int> test(-10, 20);
-	util::range<long> test2(-1000, 2000);
-	test.scale(test2, 5);
+N_INTS
 
-}
+#undef NEXTT
+#undef NEXT
+// ---
diff --git a/src/rng/crand.c b/src/rng/crand.c
index c572fba..e816102 100644
--- a/src/rng/crand.c
+++ b/src/rng/crand.c
@@ -58,6 +58,17 @@ inline static unsigned short* IFUNC_RESOLVER(_jr_st_resolv) (jr_xsub_t* restrict
 		: & IFUNC_NAME(_jr_st_resolv, low);
 }
 
+
+_fspec(readonly) internal long _jr_lastl(const struct jr_state* restrict state)
+{
+	return state->result;
+}
+
+_fspec(readonly) internal double _jr_lastf(const struct jr_state* restrict state)
+{
+	return state->fresult;
+}
+
 internal void _jr_seed(struct jr_state* restrict state, unsigned long with)
 {
 	state->st.xsubh = with;
diff --git a/src/rng/crand.h b/src/rng/crand.h
index d13d57b..faaf6b7 100644
--- a/src/rng/crand.h
+++ b/src/rng/crand.h
@@ -19,6 +19,9 @@ struct jr_state* _jr_alloc() _export(internal) __attribute__((malloc(_jr_free)))
 
 struct jr_state* _jr_new(unsigned long with) _export(internal) __attribute__((malloc(_jr_free)));
 
+double _jr_lastf(const struct jr_state* restrict state) _export(internal) _fspec(readonly);
+long   _jr_lastl(const struct jr_state* restrict state) _export(internal) _fspec(readonly);
+
 #ifdef __cplusplus
 }
 #endif